A Modified Approach of Blowfish Algorithm Based On S-Box Permutation using Shuffle Algorithm

Blowfish Algorithm has been widely analyzed and gradually accepted as a good and powerful cryptographic algorithm offering several advantages among which is suitability and efficiency for implementing hardware and software; it satisfies the basic requirements in cryptography with high in attack immunity and relatively low in algorithm complexity. In spite of undeniable success in cryptography, Blowfish (BF) still has drawbacks in the substitution and permutation of values in the substitution box (S-box) that can affect the encryption and decryption of the algorithm. This study adopted Fisher-Yates Shuffle (FYS) also known as Knuth shuffle (KS) for the permutation of S-box, and a modified Function F was used to enhance the BF algorithm to address this issue. The results show that Modified approach in Blowfish Algorithm outperformed the Original Blowfish in the encryption, decryption, and throughput of the algorithm.